The surfaces of many structures, such as many aircraft exterior and interior surfaces, are susceptible to the buildup of ice, water, and other contaminants that can interfere with the uses of such surfaces. For example, the buildup of ice, water, and/or other contaminants on aircraft wings, propellers, rotors, and other functional surfaces can interfere with or degrade the operating performance of the aircraft. When such buildups occur, much time and cost can be expended in the removal thereof. As another example, contaminants, such as dust, dirt, and food residue, can buildup on vehicle interior components and provide an unclean or non-sanitary environment within a passenger cabin.
To prevent or mitigate the stated buildup, hydrophobic surfaces, which tend to repel water, are utilized. The surface tension of the hydrophobic surface is directly related to its ability to repel water. As surface tension decreases water droplets have increased preference to cling to themselves as opposed to the surface. When the self-clinging preference becomes large enough such that the water droplets bead up into nearly perfect spheres, the surface is considered a superhydrophobic surface.
A superhydrophobic surface is formed by creating a microscopically rough surface containing sharp edges and air pockets in a material of poor wetability (that is, a material that is not easily wetable and sheds water well). On a superhydrophobic surface, a drop of water will form a nearly spherical bead that will roll when the surface is tilted slightly. Thus, superhydrophobic surfaces shed water and snow easily. Furthermore, superhydrophobic surfaces resist soiling by water-borne and other contaminants, and are easily cleaned and useful in directing flow in microfluidic devices.
Superhydrophobic surfaces can be formed through embossing, molding, or machining rough surfaces in a hydrophobic material. However, over time as the surfaces become worn away by abrasion, the smoothness of the surfaces increases, and consequently the water-shedding behavior thereof is reduced or nonexistent. When the water-shedding behavior is lost, the water undesirably tends to stick in place and/or be absorbed by the surface.
Thus, there exists a need for an improved technique of forming superhydrophobic surfaces that increases the water-shedding life span thereof and/or allows for the restoration of the superhydrophobic material properties of the surfaces.